Stretchable Electrochemical Sensor for Real‐Time Monitoring of Cells and Tissues

Abstract

Stretchable electrochemical sensors are conceivably a powerful technique that provides important chemical information to unravel elastic and curvilinear living body. However, no breakthrough was made in stretchable electrochemical device for biological detection. Herein, we synthesized Au nanotubes (NTs) with large aspect ratio to construct an effective stretchable electrochemical sensor. Interlacing network of Au NTs endows the sensor with desirable stability against mechanical deformation, and Au nanostructure provides excellent electrochemical performance and biocompatibility. This allows for the first time, real-time electrochemical monitoring of mechanically sensitive cells on the sensor both in their stretching-free and stretching states as well as sensing of the inner lining of blood vessels. The results demonstrate the great potential of this sensor in electrochemical detection of living body, opening a new window for stretchable electrochemical sensor in biological exploration.

Mechanical Distension Induces Serotonin Release from Intestine as Revealed by Stretchable Electrochemical Sensing

“…The preparation of this stretchable sensor is illustrated in the Supporting Information (Supporting Information, Figure S1). Briefly, the AuNTs electrode was fabricated by galvanic displacement of sacrificial Ag nanowires, as described in our previous report . Subsequently, 3‐aminopropyltriethoxysilane‐functionalized TiO 2 NPs (Supporting Information, Figure S2) with a positive charge were assembled onto the AuNTs networks by electrophoretic deposition .…”

“…5-HT molecules can be oxidized electrochemically,but the oxidation product is easily absorbed on the electrode surface. [6,8] Despite the antifouling performance of CNTs and the much lower contamination rate on the CNTs/TiO 2 NPs/ AuNTs sensor compared with that on electrodes free of CNTs (Supporting Information, Figure S12), the EC response of the sensor attenuated with continuous oxidation of ah igh concentration of 5-HT (Figure 3d;S upporting Information, Figure S11c;0 .5 mm 5-HT was used to accelerate the oxidation product aggregation). As with this kind of stubborn adsorbates,i nterlayered TiO 2 NPs could photodegrade these contaminants into CO 2 and H 2 Ow ithout structure damage (Figure 3e).…”

“…[6] Ther esults suggested that mucosal 5-HT was linked to colonic longitudinal and circular muscle stretch rather than phasic contractions.N evertheless,t his seminal experimental configuration was not fully satisfactory because the tubular intestine was destroyed and the intrinsic circular contraction and distension of peristaltic movements could not be reconstructed. To further relate the 5-HT release with contraction, printed sensors with ap ellet shape were developed and 5-HT overflow monitored in circular muscle contraction; [7] however,t he fixed shape and size limited mimicry of the dynamic stretch/distension of intestinal motility.T herefore,n ew approaches are still highly desired to deal with the inexplicit relationship between mucosal 5-HT and gastrointestinal motility.Recently,stretchable EC sensors based on engineered one-dimensional nanomaterials (for example,c arbon nanotubes,g old nanotubes or nanowires) have emerged [8] that induce cell deformation directly and simultaneously monitor as tretch-triggered biochemical response. [8d] This offers ap romising device for the real-time sensing of soft and elastic tissue during mechanical deformations.…”

A Stretchable Electrochemical Sensor for Inducing and Monitoring Cell Mechanotransduction in Real Time

“…[7] Although offering good stretchable properties,t he detection sensitivity and mechanical stability were still not sufficient to detect very weak transient signals from cells triggered by stretch strains only (Supporting Information, Figure S1). [7] Although offering good stretchable properties,t he detection sensitivity and mechanical stability were still not sufficient to detect very weak transient signals from cells triggered by stretch strains only (Supporting Information, Figure S1).…”

“…However,t od ate, despite several stimulating progresses in stretchable physical sensors [5] and very few emerging successes in wearable and stretchable electrochemical devices, [6] no breakthrough concept has emerged for inducing cell mechanotransduction while investigating it in real-time by asingle electrochemical device.Recently,w er eported as tretchable electrode based on AuNT networks deposited on polydimethylsiloxane (PDMS) films. [7] Although offering good stretchable properties,t he detection sensitivity and mechanical stability were still not sufficient to detect very weak transient signals from cells triggered by stretch strains only (Supporting Information, Figure S1). We now establish that relying on ah ierarchical percolation network of CNTs and AuNTs (Figure 1a)fulfills these important constraints.I ts hybrid nanostructure endowed the sensor with excellent and reproducible mechanical compliance,h igh electrical stability,s ensitive electrochemical performance,a nd cellular compatibility,a llowing sensitive and real-time monitoring of very weak transient chemical signals released by cells submitted to mechanical strains by the sensor itself.U sing this unique sensor, the stretch-induced production of small chemical effectors (NO and possibly H 2 O 2 )f rom endothelial cells,a sw ell as the stretch-triggered NO release from epithelial cells,w ere successfully monitored, providing ap romising way toward Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.…”